FacetWP Wordpress Plugin - extra spacing when using hierarchy in dropdown

I am using the Wordpress plugin FacetWP to filter my search results from a custom taxonomy.

The way I have done tit means that the sorting feature doesn't work as it gets confused as there are other characters other than numbers/letters (I'm guessing this is the problem)

To sort them into the correct order in the dropdown list I arranged them in the admin area to be hierarchical so that they were in order. This has fixed this problem, but as expected it has now staggered them adding in extra   's or spaces in the html - how can I get rid of these?

Any help is appreciated - screenshots are attached,

Thanks.

via Chebli Mohamed